Various electronic devices may have reduced power consumption by operating some of the systems within these devices at lower voltages (e.g., 3.0 volts, 1.5 volts, etc.). A power supply management module within such devices can convert an input voltage to several supply domains with different output voltages and requirements. For example, various digital or analog components or modules might have different supply voltage specifications, each operating at a different supply voltage. Such devices or systems can often have several different power supply domains.
Power conversion between input and output voltages can be done with low-dropout regulators (LDOs). LDOs are generally efficient at low voltages and can provide a regulated output using input-output voltages having a small differential. A regulated output from a LDO is commonly based on a comparison of a feedback signal from the output of the regulator to a reference voltage.
For many applications, thermal noise generated by the LDO should be small, whereas the regulation speed should be high to allow the LDO to follow fast load jumps. In some cases, using a multiple-stage amplifier improves the gain of the regulator. However, the usable bandwidth is often restricted to lower the noise, particularly for higher frequencies, thus limiting the performance of the regulator for load jumps. For higher frequencies, a single-stage amplifier can have reduced noise, but the limited gain of a single-stage amplifier can result in static errors.